I picked up a 1967 Mustang convertible that looks like it came from the factory with no heater. It has a solid factory embossed cover plate with the slots showing but not cut out instead of the normal heater control cover plate. The firewall also has a factory looking cover plate where the blower would be mounted. The car came from Hawaii. I was told the factory built some Mustangs with this non-option for shipment to Florida and Hawaii. Can anyone verify this? How rare is this? Thanks, any information would be greatly appreciated.